2.1. Human Lung Carcinoma
Lung carcinomas are responsible for the majority of deaths from cancer among men and are overtaking breast carcinomas as the most frequent cause of cancer death among women. This disease can be divided into four major histological types: (1) epidermoid or squamous (30%), (2) adenocarcinoma (35%), (3) large-cell undifferentiated (15%), and (4) small-cell (20%). The term non-small cell lung carcinoma ("NSCLC") includes the following cell types: epidermoid carcinoma cells, adenocarcinoma cells, and large undifferentiated carcinoma cells.
Most cases of lung carcinomas are incurable by chemotherapy and radiation therapy. Small cell lung carcinomas may respond to chemotherapy and radiation therapy by a reduction in size, but this does not afford a total cure. Complete surgical removal of the tumor appears to be the only effective therapy. Unfortunately, however, fewer than 30% of lung cancer patients have tumors which can be totally resected at diagnosis. Of these, fewer than one-third survive 5 years after apparent complete surgical removal of the tumor. There is a great need, therefore, for methods that would make possible an earlier diagnosis of lung cancer, a better definition of the degree of cancer spread, and a more effective therapy.